The field of this invention is human and/or veterinary vaccines and diagnostics, in particular vaccines comprising Pasteurella multocida neuraminidase and/or peptides having amino acid sequences derived therefrom and oligonucleotides useful as specific hybridization probes or specific polymerase chain reaction primers, wherein said vaccines are useful in protecting animals from infection and disease caused by P. multocida and wherein the probes or primers are useful in the diagnosis of infection by Pasteurella multocida and/or in the detection of pathogenic P. multocida.
Pasteurella multocida is a gram-negative, oxidase positive rod-shaped bacterium which is a causative agent of human and animal diseases including fowl cholera, shipping fever in cattle, respiratory tract infection, abscesses and systemic infection in various animals. Humans can also be infected by P. multocida. This organism often colonizes mucosal tissue, especially in the respiratory system.
Five serotypes based on capsular antigen groupings have been described. Further typing is based on lipopolysaccharide (LPS) structure. Group A strains of P. multocida have a capsule which is mainly composed of hyaluronic acid. This capsule contributes to virulence by inhibiting phagocytosis and halogenation of bacterial proteins by the host defense system. The capsule is often lost during subcultures in vitro. Fimbriae are likely to mediate attachment to host tissue early in the infection process. Neuraminidase (sialidase) is an enzyme produced by most pathogenic strains of P. multocida; it is believed to contribute to infection and pathogenesis.
Various vaccines are available for P. multocida have been developed, with varying degrees of cross-protection for different serotypes and varying levels of effectiveness.
Because P. multocida infections pose a threat to the agricultural industry and because such infections result in significant economic losses, because veterinary care is expensive and because P. multocida can cause human infections as well, there is a longfelt need in the art for an effective, broad spectrum subunit vaccine to protect humans and animals against P. mullocida. The present inventors believe that a vaccine comprising P. multocida neuraminidase and/or immunogenic peptides derived therefrom fulfill this need. In addition, there is a need for improved methods for diagnosis of P. multocida infections.